Trialkylamine oxides are well known as surfactants and foaming agents that are used in a variety of applications, including sanitizers, cleaners, emulsifiers, fabric softeners, oil drilling lubricants, and the like. The particular application for which a given amine oxide will be preferred depends upon its functional characteristics, which in turn depend upon the nature of the alkyl substituents. The functional properties include surface tension reduction, wetting ability, and the amount and quality of the foam produced. Structural parameters include the number of long-chain alkyl groups, their length, and their degree of branching.
For example, U.S. Pat. No. 4,425,243 discloses n-octyl dimethylamine oxide, n-decyl dimethylamine oxide, and branched decyl dimethylamine oxide for use in oil and gas production, based on their ability to produce copious, stable foam. U.S. Pat. No. 4,113,631 discloses bis (2-hydroxyethyl) cocoamine oxide, dimethyl-hydrogenated tallowamine oxide, and dimethylhexadecylamine oxide, all of which contain unbranched alkyl chains, for use in combination with quaternary ammonium compounds as foaming and silt suspending agents. European Patent Application WO 92/13934 teaches the use of N-alkyl-N,N,-dimethylamine oxides (preferably containing a C.sub.12-18 straight chain alkyl group), in combination with N,N-dehydrogenated tallow N,N,-dimethylammonium chloride, in laundry rinses and dryer sheets; no evaluation of the foaming properties of these formulations is disclosed. U.S. Pat. No. 4,921,627 discloses a relatively low-foaming amine oxide containing two C.sub.6-20 straight-chain or branched-chain alkyl groups.
Unfortunately, none of these products has little or no foam, while at the same time exhibiting superior surface tension reduction and wetting characteristics. The need for such compounds in sanitizing and cleaning applications, where high foam production is detrimental, is apparent for clean-in-place and machine cleaning applications.